SLEEP 2011 Abstract Supplement

B. Clinical Sleep Science VII. Neurological Disorders and Sleep
headache over one year’s time were analyzed. As a part of their evaluation,
those patients were queried regarding their sleep, and, if appropriate,
were studied with polysomnography in an accredited sleep disorders
center. Patients with changes on the neurologic exam suggestive of cervical
radiculopathy were examined with EMG-NCV testing.
Results: Of the 700 patients who had a diagnosis of headache on initial
evaluation, 491 (70%) also had sleep diagnoses. Of these patients with
sleep diagnoses, 277 (56%) completed polysomnography examinations.
76% of the polysomnography group had upper airway resistance syndrome
(UARS) or obstructive sleep apnea (OSA). Striking in the polysomnography
group patients was the presence of concomitant cervical
radiculopathy (73 %). Of the patients with cervical radiculopathy, 50%
or more of total sleep time was spent in non-supine sleep, despite request
by the technologist to sleep supine.
Conclusion: 1. Headache is strongly associated with sleep disordered
breathing. 2. Cervical radiculopathy is strongly associated with sleep
disordered breathing, confirming a previous study. 3. Non-supine sleep
provoked by sleep disordered breathing may play a previously unrecognized
role in headache and cervical radiculopathy.
0633
SEIZURE REDUCTION FOLLOWING NASAL CONTINUOUS
POSITIVE AIRWAY PRESSURE THERAPY FOR CO-MORBID
OBSTRUCTIVE SLEEP APNEA IN EPILEPSY
St. Louis EK 1 , Berth W 2 , Zimmerman B 3 , Dyken ME 2 , Granner MA 2
1
Department of Neurology, Mayo Clinic, Rochester, MN, USA,
2
Department of Neurology, University of Iowa Hospitals and Clinics,
Iowa City, IA, USA, 3 Department of Biostatistics, University of Iowa
College of Public Health, Iowa City, IA, USA
Introduction: Co-morbid OSA is frequent in epilepsy, and treatment
with nCPAP may reduce seizure frequency but the degree of impact on
seizure outcomes remains unclear. We hypothesized that seizure frequency
would be reduced by nasal continuous positive airway pressure
(nCPAP) therapy in epilepsy patients with co-morbid obstructive sleep
apnea (OSA). We aimed to analyze the impact of nCPAP therapy on
seizure frequency.
Methods: We retrospectively analyzed 184 epilepsy patients who underwent
polysomnography between 1/1/00-5/30/09. Demographic,
seizure frequency, antiepileptic drug load, and PSG variables were recorded.
Seizure frequency was compared between epilepsy patients with
OSA (apnea-hypopnea index (AHI)>5/hour) who were compliant with
nCPAP and those who either deferred nCPAP or were non-compliant.
Group comparisons were analyzed with 2-tailed T-tests or Wilcoxon
signed rank tests in JMP or SAS (Chicago, IL).
Results: 110 (60%) epilepsy patients had OSA. Average AHI was 22.4
± 20.8. Forty-three patients received nCPAP. Of 33 patients having
pre- and post-nCPAP data, seizure frequency decreased significantly
(t=2.138, p=0.04). 79% reported seizure reduction and 61% were responders
(having a 50% or greater seizure reduction), and this effect held
when antiepileptic drugs were unchanged or reduced (n=18, p=0.01). In
patients who did not receive or comply with nCPAP therapy, there was
no significant difference in seizure frequency (n=28, t=-1.411, p=0.17).
Conclusion: nCPAP treatment significantly reduces seizure frequency,
and the degree of seizure improvement appears comparable to the effect
of adjunctive antiepileptic drug therapy. Further prospective studies of
the impact of co-morbid OSA in epilepsy patients on seizure burden and
interictal state factors crucial to quality of life (i.e., mood state, vulnerability
to antiepileptic drug adverse effects, and sleepiness/vigilance) are
warranted.
Support (If Any): University of Iowa Carver College of Medicine
Medical Student Summer Research Award; Mentored Clinical Research
Scholar Program at Iowa (K12 RR017700-05); Grant Number
1 UL1RR024150 from the National Center for Research Resources
(NCRR)
0634
VAGUS NERVE STIMULATION THERAPY ENHANCES
OBSTRUCTIVE RESPIRATIONS DURING SLEEP
Simmons JH 1,2 , Barlow S 1,2
1
Sadler Clinic Sleep Disorders Center, The Woodlands, TX, USA,
2
CSMA, Houston, TX, USA
Introduction: Vagus Nerve Stimulator (VNS) therapy has been used in
medication resistant Epilepsy with improved outcomes and utilization
has increased over the past decade. In our center we have OSA patients
with epilepsy that have VNS devices and have recognized many of these
patients have periodic obstructive breathing patterns that correspond to
their VNS stimulation settings. We sought to confirm this association
and to also determine optimal methods of treating both the patients seizures
and OSA rather than one at the detriment of the other.
Methods: The study was done in two parts. First, we reviewed all of
our patients who have both VNS devices for the treatment of their epilepsy
and who underwent NPSG testing. Next, assessment was done to
identify if there was an association between the VNS stimulation pattern
and the occurrence of OSA. In one patient modifications were made in
the VNS settings during NPSG testing to clearly confirm the association
between VNS stimulation and OSA occurrence and then modifications
were made on the VNS stimulation settings to identify parameters that
stopped producing OSA.
Results: Eight patients met our criteria of which six demonstrated OSA.
All six demonstrated OSA in a pattern that correlated to the VNS stimulation
rate. PAP titration was performed and initially prevented OSA
from occurring during sleep. In three patients over time OSA worsened.
Repeat titrations were performed and a clear pattern of periodic OSA
was identified that was not adequately treated by prior CPAP pressures.
To address the above observation one patient thus far was further
evaluated by a repeat PAP titration. During the study, clear periodic obstructive
apneas again occurred in accordance with her VNS settings.
Stimulator parameters were modified to identify parameters that would
not precipitate OSA. Lowering the stimulation rate from 25Hz down to
10 Hz resolved the precipitation of OSA during the study.
Conclusion: We claim that OSA is a potential complication of VNS
therapy. This can be managed adequately but must be recognized when
present. VNS stimulation parameters may require modification to optimize
OSA treatment. We will present the clinical significance of these
findings in relation to treating both OSA and Epilepsy. Further study is
clearly needed on this topic since VNS is a useful treatment in Epilepsy
patients.
0635
NOCTURNAL SEIZURES AND DYSREGULATION IN THE
AUTONOMIC NERVOUS SYSTEM
Kawai M 1 , Thapalia U 1 , Ohki N 2 , Verma A 1
1
Neurology/Neurophysiology, Neurological Institute, The Methodist
Hospital, Houston, TX, USA, 2 NoruPro Light Systems, , Kokubunnji
city, Japan
Introduction: There are several reports that nocturnal seizures and sudden
unexpected death in epileptic patients (SUDEP) is related. Correlation
of autonomic nervous system (ANS) dysregulation and SUDEP
has been recognized. Heart rate variability (HRV) has been utilized to
evaluate ANS. High frequency (HF) component (0.15-0.4 Hz) of HRV
is known to represent parasympathetic modulation. HF tends to appear
steadily in normal NREM sleep. Temporal correlation between ANS and
nocturnal seizure is not known well. Complex demodulation analysis of
HRV allows us to detect dynamic changes in HF with temporal resolution
of 6.25 seconds, whereas other analyses (i.e. fast Fourier transform)
have that of 1-2 minutes.
Methods: All of the nocturnal seizures captured in our epilepsy monitoring
unit from January 2008 to September 2010 were reviewed retrospectively.
Electrocardiogram data were analyzed with complex
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SLEEP, Volume 34, Abstract Supplement, 2011